2004–2008 Yamaha Raptor 50 YFM50 ATV Factory Service Manual (P/N LIT-11616-17-13)

The Yamaha YFM50 Raptor 50 service manual (LIT-11616-17-13, first edition) covers the 5YF1 model's 49 cm³ air-cooled, four-stroke SOHC engine, automatic centrifugal clutch, and shaft drive.

Text search and wiring detail: Chapter text is searchable, with 11 embedded bookmarks linking to the contents, all nine chapters, and the full wiring diagram. The cover and lettering in some illustrations are not searchable. Small circuit labels require zooming; the final wiring diagram supplies the complete layout beyond the cropped subsystem views.

• Engine repair: Engine removal, cylinder-head and valve work, piston inspection, crankcase separation, timing-chain tensioner adjustment, and trochoid oil-pump checks.

• Clutch and transmission: Automatic centrifugal-clutch overhaul, friction-plate height adjustment, and inspection of the shift shaft, shift fork, and shift drum.

• Carburetor service: Mikuni VM16SH disassembly, jet and needle-valve inspection, fuel-level adjustment, idle-speed setting, and throttle-control checks.

• Shaft drive: Middle-gear shim selection and backlash measurement, rear axle/final-drive disassembly, and shaft-drive noise and oil-leak diagnosis.

• Brakes and chassis: Front and rear drum-brake repair, wheel-hub service, tie-rod and steering-knuckle inspection, toe-in adjustment, and swingarm checks.

• Electrical troubleshooting: C.D.I. ignition, starting-interlock and charging-system tests, starter-motor service, and neutral-indicator fault tracing with circuit diagrams.

Written primarily for Yamaha dealers and their qualified mechanics, this manual assumes a working knowledge of mechanical principles and machine repair.

Engine Overhaul, Valve Timing, and Lubrication

Engine overhaul coverage extends to valve-guide replacement and seat inspection, camshaft and rocker-arm wear checks, piston-ring measurements, and crankshaft inspection. Exploded assembly views are paired with job instruction charts identifying parts and their removal order.

Valve-clearance, compression-pressure, and ignition-timing checks accompany the manually adjusted timing-chain tensioner procedure. Oil Flow Diagrams and lubrication charts trace oil delivery through the engine. Component-specific torque tables, engine and final-gear oil capacities, and inspection limits provide the related service specifications.

Clutch Assembly and Shaft-Drive Repair

The clutch section distinguishes the black-marked friction plates, the separate friction plate, the two clutch-plate types, and the clutch-boss one-way cam. Its plate-selection chart documents how friction-plate height is established during assembly.

Middle-gear coverage explains shim selection after replacement of gears, the bearing housing, or the crankcase. Backlash measurement calls for Yamaha's gear lash measurement tool YM-01467 / 90890-01467 and pinion gear fix clamp YM-04129 / 90890-04129.

The shaft-drive troubleshooting section connects rumbling, whining, and clunking symptoms with possible bearing, backlash, and gear-tooth faults. A specific caution in the middle-driven-shaft procedure addresses thread damage caused by direct hydraulic-press loading.

Mikuni Carburetor and Throttle Controls

Carburetor inspection covers the float, needle valve, piston valve, choke movement, and metering jets. The fuel-level procedure identifies gauge YM-01312-A / 90890-01312 and includes the associated float adjustment.

Throttle free-play and speed-limiter adjustments are documented in the maintenance chapter, alongside foam air-filter and exhaust spark-arrester service.

Drum Brakes, Steering, and Suspension

Brake instructions cover shoe and drum inspection, wear-indicator alignment, brake-cam installation, and cable adjustment. Steering documentation includes tie-rod orientation, steering-stem bushings, and toe-in measurement.

Suspension coverage addresses shock-absorber inspection and replacement, swingarm bushings, and the rear dust boot. Brake and steering repairs require proper training and adherence to the manual's safety precautions.

C.D.I. Diagnosis and Starting Interlocks

Electrical troubleshooting charts address no-spark, no-crank, charging, and neutral-indicator faults. The starting-circuit operation diagram and relay tests help distinguish a neutral-switch or rear-brake interlock fault from a starter-motor problem.

Pickup- and source-coil resistance checks, rectifier/regulator diagnosis, and starter brush and armature inspection are documented separately. Electrical specifications provide the corresponding resistance, continuity, and charging-voltage references.

The Ignition System, Electric Starting System, and Charging System circuit diagrams accompany Cable Routing views. The complete YFM50S Wiring Diagram identifies components, connector arrangements, and wire-color codes.

PDF Contents and Page Breakdown

One printable, English-language 235-page PDF contains 220 chapter pages, 12 introductory and contents pages, two cover pages, and one full wiring-diagram page. All cover, introductory, and diagram pages are already included in the total.